SDF-1-induced actin polymerization and migration in human hematopoietic progenitor cells

Exp Hematol. 2001 Dec;29(12):1456-64. doi: 10.1016/s0301-472x(01)00740-8.

Abstract

Objective: The capacity of hematopoietic progenitor cells (HPCs; CD34(+) cells) to respond to chemotactic stimulation is essential for their homing efficiency, e.g., during stem cell transplantation. Previous studies established that stromal cell-derived factor-1 (SDF-1) and its receptor CXCR-4 play an important role in the homing of HPCs. The aim of the present study was to analyze SDF-1-induced actin polymerization and migration of HL-60 cells and primary human CD34(+) cells.

Materials and methods: SDF-1-induced migration of CD34(+) cells from cord blood (CB) and peripheral blood (PB) across fibronectin-coated filters was measured in a Transwell assay. Actin polymerization was detected using fluorescent phalloidin and analyzed by confocal microscopy and FACS analysis.

Results: SDF-1 induced a rapid and transient increase in actin polymerization and in polarization of the actin cytoskeleton in primary CD34(+) cells and HL-60 cells. SDF-1 was found to induce significantly more actin polymerization in CB CD34(+) cells that show fast migration in vitro compared to slow migrating PB CD34(+) cells. Moreover, CB CD34(+) cells that had migrated toward SDF-1 showed an elevated and prolonged rise in F-actin upon second exposure to SDF-1 compared to nonmigrated cells, although both cell types expressed equal levels of the SDF-1 receptor CXCR-4.

Conclusions: The relatively high migratory capacity of CB-derived human HPCs is not related to cellular polarization or high expression of the SDF-1 receptor but is largely determined by their capacity to efficiently polymerize F-actin in response to SDF-1.

MeSH terms

  • Actins / metabolism*
  • Breast Neoplasms / pathology*
  • Cell Movement / physiology*
  • Chemokine CXCL12
  • Chemokines, CXC / pharmacology*
  • Female
  • HL-60 Cells
  • Hematopoietic Stem Cell Mobilization
  • Hematopoietic Stem Cells / cytology*
  • Hematopoietic Stem Cells / physiology
  • Humans
  • Kinetics
  • Lymphoma / pathology*
  • Time Factors

Substances

  • Actins
  • CXCL12 protein, human
  • Chemokine CXCL12
  • Chemokines, CXC